One of the main types of arming of modern tactical and short-range missiles are cassette warheads based on nonguided blast-fragmentation submunitions that are widely used to kill group targets. The fullscale testing (flight tests) is an integral part of their creation. In the process of flight tests of tactical and shortrange missiles with cassette warheads, the safety issues are topical. Based on the capabilities of existing test ranges, it is planned to conduct such tests for the tactical and short-range missiles, being under development in Ukraine, in the Black sea water area where the cassette warheads with nonguided blastfragmentation submunitions (or their equivalents) will pose major hazard for ships. In the paper, two mathematical models are proposed to assess probability of killing (risk) a ship that may be present in the impact area of submunitions (submunitions equivalents) of cassette warhead. The first model was constructed in the assumption that the coverage area of cassette warhead and group dispersion of submunitions are known. Such model may be used to determine safety in the initial phases of cassette warheads development. The second model assumes that the configuration of cassette warhead and the scheme of submunitions firing were finalized, and accordingly, the nominal impact points of submunitions and their group and ind ividual dispersion are considered to be known. Practical application of both models requires the use of numerical procedures.